1. Field of the Invention
The present invention relates to a disc cartridge container case for containing a disc cartridge containing a disc used as a recording medium of an information signal such as an optical disc and a magnetic disc.
2. Description of the Prior Art
A disc cartridge containing a disc used as a recording medium is contained in a disc cartridge containing apparatus during a storage period while not used on a disc recording and/or reproduction apparatus.
The disc cartridge containing a disc has an opening for exposing a part of a signal recording area of the disc outward for recording and/or reproduction. The disc cartridge has shutter for closing the opening so as to prevent deterioration of the disc due to foreign matters including dust intruding via the opening into the cartridge during a storage period.
If the shutter is unintentionally operated during a storage period of the disc cartridge so as to open the opening for recording and/or reproduction, it becomes impossible to prevent intrusion of foreign matters including dust.
To cope with this, as well as to prevent shock due to a falling object, the disc cartridge is normally contained in a container case.
Such a container case is disclosed in Japanese Patent Publication A-5-42986 1 filed by the applicant of the present invention. The container case disclosed in this publication is made from a synthetic resin sheet material folded into a bag shape, which cannot guarantee a sufficient mechanical strength. If a strong shock is applied due to a falling object to the case, a disc cartridge inside may be deteriorated.
The container made from a sheet material folded has a problem that the sheet material cannot be bent with a high accuracy and the disc cartridge contained may be fallen from the case.
In order to solve these problems, the applicant of the present invention has suggested a disc cartridge container case disclosed in Japanese Patent Publication A-5-278772 2 for a sufficient protection of the disc cartridge inside. The case disclosed in this publication has case main body having a rectangular bottom plate with three sides provided with a rise wall and a top plate facing the bottom plate so as to define an opening for mounting/removing the disc cartridge.
The container case disclosed in publication 2 has the case main body and the top plate that can be made from a material which can guarantee a sufficient mechanical strength, so as to protect the disc cartridge contained. The container case disclosed in 2 is made from an acrylonitrile butadiene styrene resin (ABS) or high-impact polystyrene (Hi-PS) having a high shock resistance. These resins are usually not transparent. Accordingly, if the entire case is made from these resins, it becomes impossible to see the inside through the case so as to identify the type of the disc cartridge contained inside.
In order to solve these problems, there has been suggested a case that guarantees a high shock resistance and has a top plate made from a transparent resin such polystyrene (PS) and acrylonitirile styrene (AS).
However, if only the top plate is made from a transparent material, it is impossible to see both sides of the disc cartridge contained.
There has been suggested a container case having a case body made from a transparent PS resin or AS resin so that both sides of the disc cartridge contained can be seen. However, if the entire case is made from a transparent PS resin or AS resin, it becomes impossible to obtain a sufficient shock resistance and the case is easily broken when subjected to a shock such as a falling object. That is, it becomes impossible to protect the disc cartridge contained.
In order to guarantee the shock resistance as well as enable to see both sides of the disc cartridge contained, there has been suggested a case having a case main body and a top plate made from a transparent PC (polycarbonate) or a transparent ABS resin having a high shock resistance. However, these resins are expensive and the material cost is significantly increased, which in turn significantly increases the production cost.
The aforementioned disc cartridge container cases intend to sufficiently protect a disc cartridge contained as well as enable to see both sides of the disc cartridge contained by using a limited range of the material used. This limit in the material also restricts the design of the container case.